I have an 03 Dodge Dakota 3.9, 149k. Has a rough idle and sometimes drops below 500 rpm’s. Changed out intake manifold gasket, throttlebody gasket, Repaired all vacuum leaks, plugs wires, distributor, MAF, TPS, IAC, all four O2 sensors, camshaft positioning sensor, crank sensor, temp sensor, all fuel injectors and O-rings, and a few other things. Compression on all cylinders is between 130, and 140. Fuel pressure is at 95psi. Still have code P0171 and P0174 with a rough idle, and fuel doesn’t last while driving due to consumption. Scan tool says STFT on both banks are roughly between -3 and 5. LTFT on both banks is constant at 32.

 

95 psi fuel pressure are you serious? That's about double what it should be. Big clue there

 

I agree ,that is way too high on fuel pressure.
Did you use oem mopar brand on sensors?
The dakota hates off brand sensors especially 02 an TPS,MAP,IAC!

 

Uhh...how many PSI at the rail?

 

This is out of the 2000 service manual

FUEL PUMP PRESSURE TEST

(1) Remove protective cap at fuel rail test port.
Connect the 0–414 kPa (0-60 psi) fuel pressure gauge
(from gauge set 5069) to test port pressure fitting on
fuel rail (Fig. 8). The DRB III Scan Tool along
with the PEP module, the 500 psi pressure
transducer, and the transducer-to-test port
adapter may also be used in place of the fuel
pressure gauge.

(2) Start and warm engine and note pressure
gauge reading. Fuel pressure should be 339 kPa 6 34
kPa (49.2 psi 6 5 psi) at idle.

(3) If engine runs, but pressure is below 44.2 psi,
check for a kinked fuel supply line somewhere
between fuel rail and fuel pump module. If line is not
kinked, but specifications for either the Fuel Pump
Capacity, Fuel Pump Amperage or Fuel Pressure
Leak Down Tests were not met, replace fuel pump
module assembly. Refer to Fuel Pump Module
Removal/Installation.

(4) If operating pressure is above 54.2 psi, electric
fuel pump is OK, but fuel pressure regulator is defective. Replace fuel filter/fuel pressure regulator. Refer to Fuel Filter/Fuel Pressure Regulator Removal/Installation for more information.

(5) Install protective cap to fuel rail test port.

 

It was a typo. It’s not 95 psi if I remember right it was about 45 to 55

 

This weekend I’ll check the fuel pressure at the rail. The guy that did it before worked at the Dodge dealership.

Every sensor I used in the truck is all OEM, nothing aftermarket.

 

MAP you replaced also ,correct ? You had MAF.

 

Yeah I replaced the map as well. Sorry for all of the typos, I was at work when I filled out this form

 

I think honestly the only thing left, is to get my truck a stripper pole. All of the money I’ve thrown into it or at it.